it's being held at the city's holy cross cathedral, where president obama attended a ceremony earlier this week. cardinal o'malley also plans to celebrate the tragedy's first responders. afterwards, parishioners will gather for a victims' memorial near the marathon finish line. a solemn salute in boston for murdered m-i-t police officer sean collier. people joined many of boston's finest last night for funeral services for the 26-year-old. police say he was gunned down by the suspected bombing suspects while sitting in his patrol car.. collier grew up about 20 miles north of boston in wilmington, massachusetts. in january 2012, he joined the m-i-t police force with its nearly 60 officers. people also held a candlelight vigil last night in his hometown, remembering officer collier and all the victims. >> thousands of runners are lacing up their shoes. to take part in the annual 'presido 10' run. it's just about to begin. kron 4's mike pelton is live at chrissy field. >> reporter: >> there is going to be a 10 mi. run. and the 5 k run. many of them will start here, go to golden gate, and